Australian journalist Peter Greste, who with two of his al-Jazeera colleagues is being tried in an Egyptian court for colluding with the Muslim Brotherhood to falsify news, has described their ordeal as “a massive injustice regardless of the outcome”.

Mr Greste, Canadian Egyptian bureau chief Mohamed Fahmy and their Egyptian producer Baher Mohamed, along with 17 others being tried in absentia, are accused of conspiring with the now-banned Brotherhood to damage Egypt’s reputation.

The seventh day of their trial in an Egyptian court coincided with World Press Freedom Day, an irony lost on no one who attended the court.

“You cannot have a free society without a free press,” Mr Greste said from the defendant’s cage during a break in court proceedings. “In Egypt today you cannot provide balance [while there is the threat that] you can end up in prison like us.

“We recognise the significance of this trial falling on World Press Freedom Day, this is a very clear message.”

The three al-Jazeera journalists have been in prison since they were arrested on December 29 and although they deny the charges and the court has yet to see any evidence to back the prosecution’s claims, bail has repeatedly been denied.

“We've spent nearly 130 days in jail,” Mr Greste said. "It feels like a massive injustice regardless of the outcome."

Mr Fahmy was allowed briefly out of the cage to directly address the judge on Saturday, where he attempted to explain how a news bureau works.

He told the court journalists are required to speak to a wide range of people, from the military, security services, liberals and Islamists, as well as all sides of the political spectrum, including the Muslim Brotherhood.

“This is journalism, it’s my job,” Mr Fahmy said.

Afterwards he said: “I feel like the court is starting to understand what we do for a living".

Their trial and Egypt’s ongoing campaign of harassment and intimidation of the local and foreign media has drawn harsh criticism from human rights groups.

After their hearing, which was adjourned until May 15, the court extended the detention of another al-Jazeera journalist for another 45 days.

Abdullah Elshamy, a journalist with the broadcaster’s Arabic network, was arrested in August 14 after covering the violent dispersal of the pro-Brotherhood demonstration at Rabaa al-Adawiya Mosque.

“I have been on a hunger strike for 103 days … I have lost 35 kilos,” he said from the caged dock before his trial, where he was kept with dozens of other defendants.

Despite repeated requests he has yet to see a doctor, and says he has not seen a lawyer since he was detained eight months ago, he said.

“We are 15 people in a cell of 12 square metres … there is no water for 12 hours a day,” said Mr Elshamy, who described his prison conditions as squalid.

The media was forced to leave the court before Mr Elshamy’s matter started.

Egypt’s security officials say at least 16,000 people have been arrested and jailed in its campaign to “fight terrorism”, although human rights groups warn the figure could be much higher.

Since the Muslim Brotherhood-backed president Mohamed Mursi was forced from power on July 3, the military-backed interim government has undertaken a widespread crackdown on the Brotherhood, its leaders and supporters.

More than 1000 have been killed since Dr Mursi fell from power, and at least 3000 of the Brotherhood’s senior leaders, including Dr Mursi, are in jail, some facing the death penalty.

Al-Jazeera, the Qatari-owned news network has been caught up in the crackdown, targeted because it is perceived in Egypt as being overly sympathetic to the Brotherhood.